

interface Interf{
	public void f();
}


class Adapter implements Interf {

	@Override
	public void f() {
		System.out.println("ff");
	}

}

class Impl extends Adapter{
	@Override
	public void f(){
		System.out.println("ffff");
	}
}

public class Design {
	public static void main(String[] args) {
		Interf i = new Impl();
		i.f();
	}
}
